Oil well equipment



Feb. 23, 1943. J.' R', YANCEY 2,312,205

A OIL wELL EQUIPMENT Fiied Aug. 9,V 1941 3 Sheets-Sheet l HIH 2% 6?/ if ff "L,

Feb. 23, 1943. J, R, YANCEY 2,312,205

OIL WELL EQUIPMENT Filed Aug. 9, 1941 3 Sheets-Sheet 2 Feb. 23, 1943. J, R* YANCEY 2,312,205

oIL WELL EQUIPMENT I Filed Aug. 9, 1941 3 Sheets-Shea?I 3- www Patented Feb. 23, 1943 2,312,205 on. WELL EQUIPMENT John R. Yancey, Houston, Tex., assignor to Gray Tool Company, Houston, Tex., a corporation of Texas Application August 9, 1941, Serial No. 406,176

- 3 Claims.

This invention relates to oil well foundation equipment and auxiliary devices enabling the operator to complete the Well in the most economical manner yet with the assurance of being able to safely handle any situation which may arise.

The invention is particularly useful under conditions such as exist, for example, in the West Texas field where separate gas sands independent of the regular producing horizon may o-r may not be encountered above the regular producing horizon. Starting with the foundation equipment provided in accordance with the invention, the operator can proceed with the auxiliary equipment of the invention as the encountered conditions may dictate, much of this auxiliary equipment being in the nature of salvageable accessories. Suitable equipment and procedural steps for carrying out the invention are shown by way of example in the accompanying drawings with reference to which the description will proceed.

In the drawings:

Figure 1 is an elevation partly in section of the upper end of a casing, a head secured to the casing, and a hold-down ring on the head;

Figure 2 adds to Figure 1, in elevation, and partly in section, control equipment including a drilling master Valve and a blowout preventer;

Figure 3 is a section through the hold-down ring and adjacent portions of the head and drilling master Valve of Figure 2, the section being taken in a different plane from that of Figure 2 for the purpose of showing a preferred means of securing the parts together;

Figure 4 is an elevation partly in section showing the elements of Figure 2 with the control equipment and ring lifted away, and additionally showing an inner pipe and slips disposed around the latter ready to be moved to operative position;

Figure 5 is an elevation partly in section showing the slips of Figure 4 in operative relation in the head with the inner pipe cut off thereabove, and showing additionally a stuffing box about to be engaged with the inner pipe;

Figure 6 is an elevation partly in section show- J ing the stuffing box of Figure 5 in operative disposition between the casing head land a superposed tubing head, and showing also control equipment superposed on the latter;

Figure 7 is a view like Figure 2, but showing an inner pipe and a stripper embracing the inner pipe above the control equipment;

Figure 8 is a fragmentary view showing an enlarged axial section of the stripper of Figure '7;

Figure 9 is a view like Figure 7, but showing the stripper seated in the casing head and engaged by the hold-down means; 1

Figure 10 is a View like Figure 9, but showing the control equipmentlifted away from the holddown ring and showing, additionally, slips surrounding the inner pipe above the ring;

Figure 11 is a view like Figure 10, but showing the slips operatively disposed in the stripper, the control equipment having been swung away and the inner pipe cut oir above the hold-down ring, and additionally showing a stuing box about to be engaged with theupper end of the inner pipe;

Figure 12 is a view like Figure 11, except that the stuffing box is shown operatively disposed between the hold down ring and a superposed tubing head;

Figure 13 is a view like Figure 11 except that the hold-down ring and a removable upper portion of the stripper arev absent; and

Figure 14 is a view like Figure 13, but with the stufng box operatively disposed between the casing head and a tubing head with control equipment on the latter.

As indicated at the outset, the purpose of the invention is to provide relatively simple equipment designed to take care of arising situations in the most economical manner and for the purpose of illustration herein it will be assumed that the contemplated conditions of operation are such as may be encountered in the West Texas eld wherein upper gas sands vmay be struck. According to the invention, the simpler the operl-ation the cheaper becomes the permanent assembly left on the well. In more involved operations, more equipment is required, but much of this equipment is salvageable.

Referringnow to the drawings, and first to Figure 1, referencel numeral 2|) designates an outer casing which has been run in and cemented and has been equipped with a head 2| having an annular bolting ange 22 and an upwardly faced conical internal seat 23. Supported on flange 22 through the intermediary of a packing ring 24 is a hold-down ring 25 equipped with a number of radially disposed set screws 26 whose threaded inner ends are engaged in threaded bores in the ring 25 and whose outer ends are passed through stuffing boxes equipped with gland nuts as at 21. The outer ends of the screws 26 may be squared for engagement by a turning tool, their inner ends being beveled. The inner diameter of the ring 25 is substantially the same as the maximum diameter of seat 2,3, the outer diameter of the ring being substantially the same as the outer diameter of flange 22, as here shown.

In Figure 2, control equipment including a drilling master valve 23 and a blowout preventer 23 is shown superposed on ring 25, the drilling master valve having a flange 3l) of the same diameter as ring 25 and the casing head flange 22, a packing ring 3| being interposed between ila-nge `3! and ring 25.

The casing head, hold-down ring, and control equipment constitute foundation equipment from which the operator may Work to take care of the encountered conditions in the simplestI and most economical manner. The control equipment includes essentially the drillingmaster -valve Vand desirably a blowout preventer, as shown. If desired, a second blowout preventer may be added.

In Figure 2, the drill D is about tobe lowered for the drilling-in operation. Depending on whether or not the gas sand is struck, it may be that after the inner string -of pipe is lowered the operator will wish to lift off the control equipment and therewith the ring ,25, or to lift 01T the control equipment leaving the ring 25 secured to the casing head. lIn order that this choice may be exercised, I provide independent means for securing the ring to the casing head and for securing the control equipment to the ring. An example of such an arrangement is shown in Figure 3.

Referring to Figure 3, the ring 25 is provided with a number of bores as at 32, these bores being threaded throughout, and being parallel to the axis of Vthering and equally spaced apart on a common circle, The casing head flange 22 and the flange 33 of the drilling master valveare provided with unthreadedY bores registering with the bores 32 of ring '25. Threaded studs as at 33 are passed through the bores of ange 22 and screwed half-Way intatte .bores 3.2. .nuts as at 3 4 beine threaded on the lower ends of the studs so that ring 25 is securelyattached to the casing head. Threaded studs as at 3,5 are passed through the bores of flange 30 and screwed into ,the bores 32 until they Vstrike .Studs 3?., nut-S 3.5 being applied to the upper ends of studs 35 so that the drilling master valve is securely attached to ring 25.

If everything goes well and upper gas sand is not enounteledbefore reaching the Oil sand, the procedure disclosed in Patents 2,082,413 or 2,117,- 444, respectively issued on June l, 1937, and May '17, i938, to Robert A. Mueller and myself, may be followed and since there will now be no occasion to'use the hold-down ring 25, the studs 33 can be removed `so that thering will be lifted away with the controll equipment.

In Figure 4 is tassumed that no gas has been encountered, but that the pipe 31 has stuck offbottom. Ring 25 has been lifted away with the control equipment and slips 38 applied to the pipe. A slip type hanger such as is disclosed in Patent No, 2,207,469, issued to Richard P. Roye, July 9, 1940, could be employed and a Weld could be formed in accordance with this last-mentioned patent, since no gas has been encountered. In Figure the slips are shown engaged with seat 23 of the casing head and supporting the pipe which has been out off a distance above the head. Reference numeral.39 designates a stufng box which is about to be applied tothe upper end of the pipe, this stuingbox including, for example, a neoprene impregnated cotton fabric Vpacking cup 40 so as to beable to afford a relatively long lived seal.

' Figure 6 shows the stuning box 3S operatively engaged with the pipe 31 and clamped between the casing head 2| and a tubing head 4| on top of which is secured control equipment including a drilling master valve 42 and a blowout preventer 43, the drill D being about to be lowered through the equipment for the next drilling operation. Completion of the well will be assumed to follow in the ordinary` manner.

.It will now be assumed that a stratum of gas sand'has been encountered above the oil sand. After the inner casing has been run in and cemented, it may be found that due to low pressure of the s and it has been effectively sealed off by the cement and whether this is the case can, of coursabe determined at the casing head. However, if the gas. pressure is high enough or the drilling mud is light the gas will cut the cement thereabove rendering the cement ineffective as a seal. It is to be understood that the gas sand referred to may be anywhere from 50 to 2000 feet or more above the regular producingsand.

In Figure 7 thefoundation .equipment is exactly the same ,as4 in Figure V2, `including the `casing head 2l, the hold-down ring 25, and the control equipment. In thisv case, however, itis assumed that the upper gas sand has been encountered. A stripper S hasbeen applied to the pipe, this stripper, as particularly shown in Figure. 8, comprising a centralconicalring portion 44 having a lower threaded ilange with which is engaged a ring portion 45 carrying a downwardly and in- Wardly converging rubber skirt 46 of eXible rubber, neoprene, `or the like, which seals against the pipe 4l, Figure '7. The stripper also includes an upper ring portion 48 engaged with a threaded Yinternal flange of ring 44. Ring 48 is substantially cylindrical, whereas the lower rings are tapered substantially as the casing head seat 23.

With the set screws 2S retracted as in Figure 7, the stripper is lowered through the control equipment and ring 25 and landed on seat 23, the screws 26 being then screwed inwardly so as to engage an upper, outerftapered portion 49 of ring 43 so thatthe stripper is firmly seated and held down, an Vouter. seal being effected by sealing rings carried by ring portion 44. The pipe 47 is now lowered into the Well with the stripper acting as the principal control means, preventing the escape of .gas from ybetween the inner and outercasings. Pressure may be relieved through the vents (side outlets) in the casing head, if the pressure between the casing strings is strong enough to overload the stripper.

The pipe 47 is runA into the well until the required level is` reached or until conditions arise which stopiurtherdownward movement thereof. Afterthepipe has been cemented, studs 35 are removed, leaving ring 25,'secured to theeasing head, the control equipment is elevated, and slips 50 are disposed about the pipe 4?, as shown in Figure l0. Since ring 25 is, as stated, secured to the casing head, it is still effective to yhold down the stripper.

In Figure 11 theslips 53 are shown seated in the bowl 5! of the stripper S. The pipe has been cut 01T Aa distance above. ring 25 after the ,operative disposition of theslips in the bowl, land a stuiing box 52, `exactly like stufng box'39, is about to be applied. Figure l2shows`the stuffing box operatively engaged with the pipe and clamped between ring 25 andthe rflange 53 ci a superposed tubing head AThe flange 52a of stuffing box 52 is of lessdiaineter thanthecircle on which the bores 32 of ring 25 are located and, consequently, does not interfere with the placement of the long studs 55 by which flange 53 is secured to ring 25. Studs 55 replace studs 35, Figure 3, in view of the greater length required.

The stuiiing box is used to supplement the stripper and provide a seal which will not deteriorate during the normal life of the well. The stripper skirt 46 being made of rubber, neoprene, or the like, will not last as long as the well is likely to iiow and, therefore, must be supplemented by a more permanent seal as provided by the stuffing box. Further, the stripper is likely to be overloaded by the closed in well pressure and must be supplemented by the stuiiing box in order to maintain an effective seal against pressure from above or below. It is assumed that completion will proceed in the ordinary fashion.

In the procedure just described, it has been assumed that it has not been feasible to remove ring 25. However, if the pressure between the strings is not great enough to stretch the inner string of pipe, and if the weight of the casing resting on the slips in the stripper bowl is great enough to hold the stripper down, ring 25 is salvaged as is also the upper ring portion of the stripper S. In Figure 13 it will be seen that these parts have been removed prior to the application of the stufng box, thus eifecting a considerable saving. The set up shown in Figure 14 is like that of Figure 6 except that the slips of the latter figure are replaced by the lower portion of the stripper and the slips carried thereby.

From the above it will be seen that by using the described foundation equipment the procedure can move in the required direction and that in any event the salvaging of parts for reuse is possible, thus affording the most economical operations. I, of course, do not limit myself necessarily to the described details, the scope of the invention being determined in the following claims.

I claim:

1. The combination with oil well foundation` equipment including a casing head, said head having an annular internal upwardly facing seat, control equipment including a drilling master valve above said head, and a separate ring disposed between the master valve and head, said ring having inwardly and outwardly adjustable hold-down means and an available internal diameter substantially as large as the maximum diameter of said seat, of a stripper insertable through said control equipment and ring around an inner pipe to said seat and maintainable on the latter by said hold-down means, said stripper including a bowl for the reception of slips, slip-s disposable in said bowl for the support of said pipe, and means removably securing said ring on said head independently of the control equipment so that the latter may be removed and replaced by a head for another pipe while the stripper is held down by said ring.

2. The combination with oil well foundation equipment including a casing head, said head having an annular internal upwardly facing seat, control equipment including a drilling master valve above said head, and a separate ring disposed between the master valve and head, said ring having inwardly and outwardly adjustable hold-down means and an available internal diameter substantially as large as the maximum diameter of said seat, of a stripper insertable through said control equipment and ring around an inner pipe to said seat and maintainable on the latter by said hold-down means, said stripper including a bowl for the reception of slips, slips disposable in said bowl for the support of said pipe, means removably securing said ring on said head independently of the control equipment so that the latter may be removed and replaced by a head for another pipe while the stripper is held down by said ring, and a stuffing box disposable between said ring and the second head for forming a permanent seal with the irst pipe.

3. The combination with oil well foundation equipment including a casing head, said head having an annular internal upwardly facing seat, control equipment including a drilling master valve above said head, and a separate ring disposed between the master valve and head, said ring having inwardly and outwardly adjustable hold-down means-and an available internal diameter substantially as large as the maximum diameter of said seat, of a stripper insertable through said control equipment and ring around an inner pipe to said seat and maintainable on the latter by said hold-down means, said stripper including a bowl for the reception of slips and including a separable annular portion above said bowl engageable by said holddown means, slips disposable in said bowl for the support of said pipe, and means removably securing said ring on said head independently of the control equipment so that the latter may be removed and replaced by a head for another pipe while the stripper is held down by said ring.

JOHN R. YANCEY. 

